From owner-freebsd-current@FreeBSD.ORG Tue Jun 14 16:30:50 2011 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DF0A4106566C for ; Tue, 14 Jun 2011 16:30:50 +0000 (UTC) (envelope-from kmacybsd@gmail.com) Received: from mail-vx0-f182.google.com (mail-vx0-f182.google.com [209.85.220.182]) by mx1.freebsd.org (Postfix) with ESMTP id 92EB88FC1E for ; Tue, 14 Jun 2011 16:30:50 +0000 (UTC) Received: by vxc34 with SMTP id 34so6637184vxc.13 for ; Tue, 14 Jun 2011 09:30:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=uJaSU1DyST2a/G0Ri+4asji7qSifWaGwHfT1N36t1xQ=; b=XyslQL+vWF5YIHpxeyMfm4gmNJz/dVX/f1DUWN2GgQa0z13mVxm66X+gGLdnv9bxq+ 9ZNlkZ5yYt4ACT2M30AT2NUFi0SBZEGUSYeKfNWGiZQtTcpd5prSv5CEcrMl2u/Rr6/q eSHRDXdu5hQ2JCe2zJC08cmB/821jfigK/bS8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=w1exKSbqvotiJSQ/LrmEaf9LXjXpoC+i57Djl5+Y3NWAre1/NA+38xh6NsrZrSEW3I A4v6gKWmtBhXMOLzzCwkWPI9uArWfmtjOSBvn6OICTcM4i2w2j4Y0dhizhoVRnjv8uUU kfRpaXzttUVzMXQxFZKB7oQMEI5bOr+O+zsB8= MIME-Version: 1.0 Received: by 10.52.173.111 with SMTP id bj15mr6356529vdc.122.1308069049648; Tue, 14 Jun 2011 09:30:49 -0700 (PDT) Sender: kmacybsd@gmail.com Received: by 10.52.187.74 with HTTP; Tue, 14 Jun 2011 09:30:49 -0700 (PDT) In-Reply-To: References: <20110614161105.GA17306@onelab2.iet.unipi.it> Date: Tue, 14 Jun 2011 18:30:49 +0200 X-Google-Sender-Auth: 7-2o1WEIcDGJeIRb-J2-rfI7jGk Message-ID: From: "K. Macy" To: Luigi Rizzo Content-Type: text/plain; charset=ISO-8859-1 Cc: current@freebsd.org Subject: Re: fast/syscall-free gettimeofday ? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Jun 2011 16:30:50 -0000 On Tue, Jun 14, 2011 at 6:08 PM, K. Macy wrote: > http://svnweb.freebsd.org/base/head/sys/sys/imgact.h > > kib added rudimentary support for this in January To clarify, this is just the kernel side of the shared page infrastructure, and is currently only hosting the the signal handling code. The user library side is non-existent and no data sharing currently happens. -Kip > On Tue, Jun 14, 2011 at 6:11 PM, Luigi Rizzo wrote: >> there were discussions at some point on an imprecise but >> fast implementations of gettimeofday() that would not require >> a system call (perhaps mmapping some memory region which >> is opportunistically updated). >> >> Does anyone remember what happened about that ? >> >> Otherwise, is there any place in the kernel where i can fetch >> a struct timeval which is not off by more than, say 1 tick ? >> >> cheers >> luigi >> _______________________________________________ >> freebsd-current@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-current >> To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" >> >